N,n-mono- and di-substituted-aralkyl amines



United States Patent C) 3,227,756 N,N-MONO- AND DI-SUBSTITUTED- ARALKYLAMINES Sidney B. Richter and David P. Mayer, Chicago, 111., as-

signors to Velsicol Chemical Corporation, Chicago, 111.,

a corporation of Illinois No Drawing. Filed July 10, 1952, Ser. No.208,905

Claims. (Ci. 260-5703) This invention relates to the production of newpesticidal compositions of matter. More specifically, this inventionrelates to new chemical compounds of the general formula in which n is awhole number from 1 to 3; A, B, C, D, and E are selected from the groupconsisting of lower unsubstituted alkoxy, chlorine and hydrogen, atleast 2 of A, B, C, D, and E are chlorine, a minimum of l and a maximumof 2 of A, B, C, D, and E are lower unsubstituted alkoxy, provided thatE is hydrogen when A, B, and C are lower unsubstituted alkoxy, chlorine,and hydrogen, respectively, and A is hydrogen when E, D, and C are lowerunsubstituted alkoxy, chlorine and hydrogen, respectively; and R and Rare selected from the group consisting of unsubstituted lower alkylunsubstituted lower alkenyl, lower monohydroxyalkyl, and hydrogen. Bylower alkoxy, lower alkyl, lower alkenyl, and lower monohydroxyalkyl aremeant those groups containing up to four carbon atoms. The new compoundsof this invention are useful as pesticides, particularly asinsecticides, miticides, and herbicides.

The new compounds of this invention can be prepared by the condensationof compounds of the formula wherein n, A, B, C, D, and E are as definedabove, and Y is chlorine or bromine with amines HNRR, wherein R and Rare also as defined above. Preferred starting materials of the givenformula are those in which n is one and A or B or C is lowerunsubstituted alkoxy. Suitable starting materials of the formula givencan be prepared from the corresponding aldehydes, anhydrides, orcarboxylic acid esters by reduction to the corresponding alcoholsfollowed by treatment with a reagent such as thionyl chloride. Forexample, reduction of an alkyl ester of a suitably ring-substitutedbenzoic acid with lithium aluminum hydride yields the correspondingbenzyl alcohol, which can then be treated with thionyl chloride to givethe ring-substituted benzyl chloride suitable for use as a startingmaterial in preparing the compounds of this invention. Suitable startingmaterials in which n is 2 or 3 can be prepared similarly from theappropriate phenylacetic and phenylpropionic acid esters, respectively.

Some typical carboxylic acids which can be used in the form of theiralkyl esters to be converted to appropriate starting materials for thisinvention include, for example, 2-ethoxy-3,S-dichlorobenzoic acid,2-methoxy-3,5-dichorophenylacetic acid,3-methoxy-2,fi-dichlorophenylacetic acid,2,6-dimethoxy-3,S-dichlorobenzoic acid, 2-methoxy- 3,5-dichlorobenzoicacid, 3-methoxy-Z,6-dichlorobenzoic acid, 3-methoxy-2,4-dichlorobenzoicacid, 3-methoxy-4,6- dichlorobenzoic acid,4-methoxy-2,3,S-trichlorobenzoic 3,227,756 Patented Jan. 4, 1966 iceacid, and the like. Such substituted benzoic acids are known in the artor can be prepared readily. 2-Butoxy- 3,5-dichlorobenzoic acid, forexample, can be obtained from 3,5-dichlorosalicylic acid by treatmentwith butyl bromide in the presence of silver oxide.

When alkyl esters of these benzoic acids are reduced and chlorinated asdescribed above, the resulting compounds useful as reactants inpreparing the new compounds of the present invention are2-ethoxy-3,5-dichlorobenzyl chloride, 2-methoxy-3,S-dichlorophenethylchloride, 3-methoxy-2,6-dichlorophenethyl chloride, 2,6-dimethoxy-3,S-dichlorobenzyl chloride, 2-methoxy-3,5-dichlorobenzylchloride, 3-methoxy-2,6-dichlorobenzyl chloride,3-methoxy-2,4-dichlorobenzyl chloride, 3-methoxy-4,6-dichlorobenzylchloride, 4 methoxy 2,3,5-trichlorobenzyl chloride, and2-butoxy-3,S-dichlorobenzyl chloride, respectively.

Suitable reactants of the formula HNRR include ammonia and a widevariety of primary and secondary amines wherein R and R are as definedabove. Some typical suitable reactants are, for example, isopropylamine,di-n-propylamine, dimethylamine, ethanolamine, methylamine,diethylamine, di-tert-butylamine, allylamine, diallylamine,4-amino-1-butanol, 3-amino-1-butanol, diethanolamine, methylethylamine,and the like.

When the condensation reaction to form the new compounds of thisinvention is carried out, at least two moles of the amine should be usedfor each mole of the chloride or bromide, since the hydrogen halidereleased during the reaction is taken up by some of the free amine. Thereaction can be carried out conveniently by heating the reactants,preferably in an inert solvent such as benzene or toluene. The exactreaction temperatures are not critical, since the reaction will oftentake place at normal room temperature; however, temperatures which arethe normal reflux temperature of the reaction mixture are preferred. Thereaction will often be complete in a few hours. Generally, a precipitateof amine hydrochloride or hydrobromide will form in the reaction mixtureand can be filtered off. The product can be isolated from the reactionmixture by ether extraction; and it can be purified by crystallization,fractional distillation, or other techniques known to the art. Althoughthe reaction is normally carried out at atmospheric pressure, suborsuperatmospheric pressures can also be used if desired.

The manner in which typical new compounds of this invention can beprepared is illustrated in the following examples. All temperatures arein degrees Centigrade.

EXAMPLE 1 Preparation of 4-meth0xy-3,5-dichlorobenzyl alcohol A solutionof methyl 4-methoxy-3,5-dichlorobenzoate (37.7 g.; 0.16 mole) in 750 ml.ether was added dropwise to a well-stirred slurry of 9 g. lithiumaluminum hydride in 300 ml. ether at such a rate as to maintain gentlereflux. The mixture was refluxed for 1 hr., cooled, and treated dropwiseover a period of 2 hrs. with 250 ml. of 10% H 50 The ether layer waswashed with water, dried over magnesium sulfate, and filtered.Evaporation of the ether gave an oil, which was distilled in vacuo togive 24 g. (73% of theory) of 4-methoxy-3,S-dichlorobenzyl alcohol,colorless oil, B.P. 126/ 1.5 mm., which crystallized to a white solid,M.P. 4244.

EXAMPLE 2 Preparation of 4-meth0xy-3,5-diclzlorobenzyl chloride Thionylchloride (16 g.; 0.14 mole) was added dropwise with stirring to4-methoxy-3,S-dichlorobenzyl alcohol (24 g.; 0.11 mole) and pyridine (9g.; 0.11 mole) in 250 ml. toluene. The mixture was stirred and refluxedfor 4 hrs., cooled, and filtered. The solvent and excess thionylchloride were distilled off, and the residue was distilled in vacuo togive 21 g. (85% of theory) of 4-methoxy-3,S-dichlorobenzyl chloride,pale yellow oil, B.P. 100lO3/O.7 mm., It 27/D 1.5670.

EXAMPLE 3 Preparation of N-isopropyl*4-meth0xy-3,5- dichlorobenzylamineA mixture of 250 g. 4-methoxy-3,S-dichlorobenzyl chloride, 133 g.isopropylamine, and 500 ml. benzene is stirred and refluxed for 8 hours.The cooled reaction mixture is treated with 500 ml. of 10% NaOH solutionand then shaken with 500 ml. of benzene. The benzene layer is washedwith water, dried over sodium sulfate, filtered, and evaporated. Theresidue is fractionally distilled under reduced pressure to give thedesired N-isopropyl-{t-methoxy-3,5-dichlorobenzylamine.

A Wide variety of other new compounds within the scope of this inventioncan be prepared in a manner similar to that detailed above. Given in thefollowing examples are the reactants which can be used to prepare theindicated named compounds of this invention.

EXAMPLE 4 2 ethoxy 3,5 dichlorobenzyl chloride-l-methylamine=N methyl 2ethoxy 3,5 dichlorobenzylamine.

EXAMPLE 5 2 methoxy 3,5 dichlorophenethyl chloride+di methylamine=N,Ndimethyl 2 methoxy 3,5 dichlorophenethylamine.

EXAMPLE 6 3 methoxy 2,6 dichlorophenethyl chloride-l-ethylamine=N ethyl3 methoxy 2,6 dichlorophenethylamine.

EXAMPLE 7 2,6 dimethoxy 3,5 dichlorobenzyl chloride-t-diethylamine=N,Ndiethyl 2,6 dimethoxy 3,5 dichlo robenzylamine.

EXAMPLE 8 2 methoxy 3,5 dichlorobenzyl chloride-l-propylamine N-n-propyl2 methoxy 3,5 dichlorobenzylamine.

EXAMPLE 9 3 methoxy 2,6 dichlorobenzyl chloride-t-diisopropylamine=N,Ndiisopropyl 3 methoxy 2,6 dichlorobenzylamine.

EXAMPLE 10 3 methoxy 2,4 dichlorobenzyl chloride-l-butylamine=N n butyl3 methoxy 2,4 dichlorobenzylamine.

EXAMPLE 11 3 methoxy 4,6 dichlorobenzyl chloride-t-allylamine :N allyl 3methoxy 4,6 dichlorobenzylamine.

EXAMPLE 12 4 methoxy 2,3,5 trichlorobenzyl chloride-t-diallylamine=N,Ndiallyl 4 methoxy 2,3,5 trichlorobenzylamine.

EXAMPLE 13 2 methoxy 5,6 dichlorobenzyl chloride+dimethylamine=N,Ndimethyl 2 methoxy 5,6 dichlorobenzylamine.

EXAMPLE 14 3 methoxy 4,6 dichlorobenzylchloride-t-di-n-propylamine=N,N-di-n-propyl 3 methoxy 4,6dichlorobenzylamine.

EXAMPLE 15 4 methoxy 5 ,6 dichlorobenzyl chloride+isopropylamine=Nisopropyl 4 methoxy 5,6 dichlorobenzylamine.

4 EXAMPLE 16 2 methoxy 5,6 dichlorophenethyl chloride+allyamine=N allyl2 methoxy 5,6 dichlorophenethylamine.

EXAMPLE 18 4 methoxy 2,3,5 trichlorobenzyl chloride-i-ammonia:4 methoxy2,3,5 trichlorobenzylamine.

For practical use as pesticides, the compounds of this invention aregenerally incorporated into herbicidal, insecticidal, and miticidalcompositions which comprise an inert carrier and a pesticidally toxicamount of such a compound. Such compositions, which are usually known inthe art as formulations, enable the active compound to be appliedconveniently to the site of the pest infestation in any desiredquantity. These compositions can be solids such as dusts, granules, orWettable powders; or they can be liquids such as solutions oremulsifiable concentrate.

For example, dusts can be prepared by grinding and blending the activecompound with a solid inert carrier such as the tales, clays, silicas,pyrophyllite, and the like. Granular formulations can be prepared byimpregnating the compound, usually dissolved in a suitable solvent, onto and into granulated carriers such as the attapulgites or thevermiculites, usually of a particle size range of from about 0.3 to 1.5mm. Wettable powders, which can be dispersed in water to any desiredconcentration of the active compound, can be prepared by incorporatingwetting agents into concentrated dust compositions.

In some cases the active compounds are sufiiciently soluble in commonorganic solvents such as kerosene or xylene so that they can be useddirectly as solutions in these solvents. Frequently, solutions ofinsecticides can be dispersed under superatmospheric pressure asaerosols. However, preferred liquid compositions are emulsifiableconcentrates, which comprise an active compound according to thisinvention and as the inert carrier, a solvent and an emulsifier. Suchemulsifiable concentrates can be diluted with water to any desiredconcentration of active compound for application as sprays to the siteof the pest infestation. The emulsifiers most commonly used in theseconcentrates are nonionic or mixtures of nonionic with anionicsurface-active agents.

A typical composition according to this invention is illustrated by thefollowing example, in which the quantities are in parts by weight.

EXAMPLE 19 Preparation of a dust Product of Example 3 1O Powdered talcThe above ingredients are mixed in a mechanical grinder-blender and areground until a homogeneous, free-flowing dust of the desired particlesize is obtained. This dust is suitable for direct application to thesite of the pest infestation.

The pesticides of this invention can be applied in any manner recognizedby the art. The concentration of the new compounds of this invention inthe compositions will vary greatly with the type of formulation and thepurpose for which it" is designed, but generally the compositions willcomprise from about 0.05 to about percent by weight of the activecompounds of this invention. In a preferred embodiment of thisinvention, the compositions will comprise from about 5 to about 75percent by weight of the active compound. The compositions can alsocomprise such additional substances as other pesticides, spreaders,adhesives, stickers, fertilizers, activators, synergists, and the like.

The new compounds of this invention can be used in many ways for thecontrol of insects and mites. Insecticides which are to be used asstomach poisons or protective materials can be applied to the surface onwhich the insects feed or travel. Insecticides which are to be used ascontact poisons or eradicants can be applied directly to the body of theinsect, as a residual treatment to the surface on which the insect maywalk or crawl, or as a fumigant treatment of the air which the insectbreathes. In some cases, the compounds applied to the soil or plantsurfaces are taken up by the plant, and the insects are poisonedsystematically.

The above methods of using insecticides are based on the fact thatalmost all the injury done by insects is a direct or indirect result oftheir attempts to secure food. Indeed, the large number of destructiveinsects can be classified broadly on the basis of their feeding habits.There are, for example, the chewing insects such as the Mexican beanbeetle, the southern armyworm, cabbageworms, grasshoppers, the Coloradopotato beetle, the cankerworm, and the gypsy worm. There are also thepiercing-sucking insects, such as the pea aphid, the house fly, thechinch bug, leafhoppers, and plant bugs.

Another group of insects comprises the internal feeders. These includeborers such as the European corn borer and the corn earworm; worms orweevils such as the codling moth, cotton boll weevil, plum curculio,melonworm, and the apple maggot; leaf miners such as the apple leafminer and the beet leaf miner; and gall insects such as the wheatjointworrn, and grape phylloxera. Insects which attack below the surfaceof the ground are classified as subterranean insects and include suchdestructive pests as the wooly apple aphid, the Japanese beetle, and thecorn rootworm.

Mites and ticks are not true insects. Many economically importantspecies of mites and ticks are known, including the red spider mite, thestrawberry spider mite, the cattle tick, and the poultry mite. Chemicalsuseful for the control of mites are often called miticides, while thoseuseful for the control of both mites and ticks are known specifically asacaricides.

The quantity of active compound of this invention to be used for insectcontrol will depend on a variety of factors, such as the specific insectinvolved, intensity of the infestation, weather, type of environment,type of formulation, and the like. For example, the application of onlyone or two ounces of active chemical per acre may be adequate forcontrol of a light infestation of an insect under conditions unfavorablefor its feeding while a pound or more of active compound per acre may berequired for the control of a heavy infestation of insects underconditions favorable to their development.

Weeds are undesirable plants in their growing where they are not wanted,having no economic value, and interfering with the production ofcultivated crops or with the welfare of livestock. Many types of Weedsare known, including annuals such as pigweed, lambsquarters, yellowfoxtail, crabgrass, wild mustard, French-weed, rye-grass, goose-grass,chickweed, and smartweed; biennials such as wild carrot, great burdock,mullein, round-leaved mallow, blue thistle, bull thistle, hounds-tongue,moth mullein, and purple star thistle; or perennials such as whitecockle, perennial rye-grass, quackgrass, Johnson grass, Canada thistle,hedge bindweed, Bermuda grass, sheep sorrel, field chickweed, andwinter-cross. Similarly, such weeds can be classified as broad-leaf orgrassy weeds. It is economically desirable to control the growth of suchweeds without damaging beneficial plants or livestock.

The new compounds of this invention are particularly valuable for weedcontrol because they are toxic to many species and groups of weeds whilethey are relatively nontoxic to many beneficial plants. The method ofthis invention for the control of weeds comprises contacting said weedswith a herbicidal composition comprising an inert carrier and as theessential active ingredient, in a quantity which is herbicidally toxicto said weeds, a compound of this invention. The exact amount ofcompound required will depend on a variety of factors, including thehardiness of the particular weed species, weather, method ofapplication, the kind of beneficial plants in the same area, and thelike. Thus, while the application of up to only about one or two ouncesof an active compound per acre may be sufficient for good control of alight infestation of weeds growing under adverse conditions, theapplication of one pound or more of active compound per acre may berequired for good control of a dense infestation of hardy weeds growingunder favorable conditions.

The herbicidal toxicity of the new compounds of this invention can beillustrated by many of the established testing techniques known to theart. For example, emulsifiable concentrate compositions can be dilutedwith water to concentrations equivalent to 4 pounds of the activecompound per acre. Duplicate paper pots filled With a sand and soilmixture are seeded with weeds; and immediately after seeding, the soilsurface of each pot is sprayed with an appropriately diluted testsolution. The weed growth is maintained under artificial lighting withirrigation provided by placing the porous pots in a small amount ofwater in stainless steel trays. The weeds are observed for a week to tendays; and the percent kill, injury, and stand reduction are recorded.The results indicate a high order of herbicidal activity of thecompounds of this invention. Comparable pre-planting or postemergencetests can also be used.

What is claimed is:

1. A compound of the general formula in which n is a whole number from 1to 3; A, C, D and E are selected from the group consisting of lowerunsubstituted alkoxy, chlorine and hydrogen, at least 2 of A, C, D, andE are chlorine, A, C, D, and E is lower unsubstituted alkoxy, and R andR are selected from the roup consisting of unsubstituted lower alkyl,unsubstituted lower alkenyl, lower monohydroxyalkyl, and hydrogen.

2. N,N dimethyl-Z-methoxy-5,6-dichlorobenzylamine.

3. N-isopropyl-4-methoxy-5,6-dichlorobenzylamine.

4. N (Z-hydroxyethyl)-4-methoXy-2,6-dichlorobenzylamine.

5. N-allyl-2-methoxy-5,6-dichlorophenethylamine.

References Cited by the Examiner UNITED STATES PATENTS 2,608,584 8/ 1952Sprules et a1 260570.9 2,763,616 9/1956 Brooks 260570.9 X 2,783,2772/1957 Hiltmann 260570.9 2,862,966 12/ 1958 Surrey 260570.9 2,864,67912/ 1958 Hamm et a1. 712.3 2,884,455 8/1959 Robertson et al. 260570.82,927,053 3/1960 Eden 260-570.9 2,962,531 11/ 1960 Cofi'ield 260-57 0.92,981,619 4/1961 Josephs 712.3 3,070,628 12/ 1962 Lemin 260-57093,072,472 1/ 1963 Josephs 71-2.3

OTHER REFERENCES Benington et al., J our. Organic Chem., vol. 23, pages1979-84 (1958).

Merchant et al., Jour. Organic Chem, vol. 23, pages 1774-6 (1958).

CHARLES B. PARKER, Primary Examiner.

JULIAN S. LEVITT, Examiner.

1. A COMPOUND OF THE GENERAL FORMULA